Restore recyclerview state

Question

I found some code to save and restore the state of RecyclerView after screen rotation, but it's not working.

Code:

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putParcelable(Constants.LIST_SAVED_POSITION, recyclerView.getLayoutManager().onSaveInstanceState());
}

@Override
public void onViewStateRestored(Bundle savedInstanceState) {
    super.onViewStateRestored(savedInstanceState);
    if (savedInstanceState!=null && savedInstanceState.containsKey(Constants.LIST_SAVED_POSITION)){
        Parcelable parcelable;
        parcelable = savedInstanceState.getParcelable(Constants.LIST_SAVED_POSITION);
        recyclerView.getLayoutManager().onRestoreInstanceState(parcelable);
    }
}

The old position is not restored after a screen rotation. I know that I can save integer variables, but this way seems better.

Can someone help me solve this using this approach.

Check this post, it seems works http://stackoverflow.com/questions/28236390/recyclerview-store-restore-state-between-activities — AndroidRuntimeException, Feb 16 '16 at 16:17
where do you have this code? In a fragment or did you extend RecyclerView and drop this code in? — kandroidj, Feb 16 '16 at 16:25
have you tried just debugging to see if parcelable is coming back as not null? — kandroidj, Feb 16 '16 at 16:50
@inner_class7 Looks good but it's amazing that almost every article on RecyclerViews has its focus on creating a list, but none on saving the list. It does no good to create a beautifully crafted/valuable list (say a big list of songs I want to download) and then have the list literally be destroyed if I navigate away from the list with the single press of the back button. Why wouldn't saving state code be a requirement for creating every RecyclerView list just like the other requirements: the adapter, the layoutmanager, onCreateViewHolder, onBindViewHolder and getItemCount? Thoughts? — AJW, Feb 17 '16 at 03:37

score 0 · Answer 1 · answered Feb 16 '16 at 16:19

0

you can add this to your activity in the manifist.xml to disable the activity to recreate itself ,So after screen rotation the activity save all variables.

    android:configChanges="orientation|keyboardHidden" 
     >

answered Feb 16 '16 at 16:19

user2934536

149
8

score 0 · Accepted Answer · answered Feb 16 '16 at 17:09

I found the problem. This code is being called on the fragment. But the problem was in the re-creation of the fragment in the activity. When I fixed recreating the fragment, list restores the position even without saving it state.

old code:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_supplication_detail);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    chapter = getIntent().getIntExtra(Constants.SELECTED_ITEM, 1);

    fragmentSupplicationDetail = new FragmentSupplicationDetail();
    Bundle extras = new Bundle();
    extras.putInt(Constants.SELECTED_ITEM, chapter);
    fragmentSupplicationDetail.setArguments(extras);
    transaction.replace(R.id.container, fragmentSupplicationDetail, SUPPLICATION_FRAGMENT_TAG).commit();
}

fixes:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_supplication_detail);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    chapter = getIntent().getIntExtra(Constants.SELECTED_ITEM, 1);
    if (getSupportFragmentManager().findFragmentByTag(SUPPLICATION_FRAGMENT_TAG) == null){
        fragmentSupplicationDetail = new FragmentSupplicationDetail();
        Bundle extras = new Bundle();
        extras.putInt(Constants.SELECTED_ITEM, chapter);
        fragmentSupplicationDetail.setArguments(extras);
        Log.d(Constants.LOG_TAG, getClass().getSimpleName() + ": Создаем фрагмент ");
    }else {
        fragmentSupplicationDetail = (FragmentSupplicationDetail) getSupportFragmentManager().findFragmentByTag(SUPPLICATION_FRAGMENT_TAG);
        Log.d(Constants.LOG_TAG, getClass().getSimpleName() + ": Восстанавливаем фрагмент ");
    }
    transaction.replace(R.id.container, fragmentSupplicationDetail, SUPPLICATION_FRAGMENT_TAG).commit();
}

score -1 · Answer 3 · answered Feb 16 '16 at 16:18

I was recently working with recycler view and wanted to have the same functionality as you want, I have followed the below mentioned tutorial,even after rotating the screen It maintains the state of the view.Please refer to the following link.

http://www.androidtutorialpoint.com/material-design/listing-items-using-recyclerview/

Hope This helps !!

Restore recyclerview state

3 Answers3